Catheters are flexible medical instruments that facilitate withdrawal and introduction of fluids from and to body cavities, ducts, and vessels. Catheters may have particular application, for example, in a hemodialysis procedure where blood is withdrawn from a blood vessel for treatment, and subsequently returned to the blood vessel for circulation. During some hemodialysis procedures, a multiple lumen catheter is inserted into a body and blood is withdrawn through an arterial lumen of the catheter. The removed blood is directed, via an extension tube, to a hemodialysis machine which dialyzes the blood to remove waste and toxins. The purified blood is then returned through a venous lumen of the catheter.
The efficiency and performance of a hemodialysis procedure may be reduced due to unbalanced flow between the arterial and venous lumens and/or low recirculation at the tip of the catheter, as well as occlusion due to thrombus formation at the tip openings.